Fault phenomenon: The indoor unit works normally, with both power and operation indicator lights on, but the outdoor unit does not work.
Analysis and inspection: Since the operation indicator light is on, it indicates that the microprocessor of the indoor unit has issued a command to start the compressor, so it is estimated that there is a fault in the outdoor unit. After disassembling the outdoor unit, the LED101 (DC 280V) indicator light was observed to be on, indicating that the rectification and filtering circuit is working normally. After unplugging the compressor overheating protector, it was observed that the LED201 indicator light did not light up, indicating no +5V supply voltage. Upon checking the switch power supply circuit on the control board, it was found that when measuring the voltage across the start-up resistor, the LED201 lit up and the switch power supply oscillated, indicating that R2 was open-circuited. Data source: Beijing Changhong Air Conditioner After-sales Service Phone Number http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3766321.
Handling method: After replacing R2 and reconnecting the compressor overheating protector, the fault was eliminated. For Changhong inverter air conditioners, the outdoor unit does not work.